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Monthly Archives: October 2012

World War Z? Certainly looks like it. A planet though to be buried has come back alive… undead, some might say. Coincidentally, the analysis of Hubble Space Telescope’s observations came right before Halloween. The massive alien zombie planet, called the Fomalhaut b (the name even sounds creepy, if you ask me), orbits the star Fomalhaut, which is 25 light years from the constellation Piscis Austrinus. These recent discoveries, however, contradict conclusions in November 2008 that indicated Fomalhaut b as a giant dust cloud. Fomalhaut b, three times smaller than Jupiter, was the first planet directly imaged in visible light. The planet seems to be inside a vast debris ring. Because the scientists did not discover any brightness variations in the 2004 and 2006 Hubble observations, they concluded that Fomalhaut b must be a massive planet. Watch the Halloween-themed video below on the Zombie Planet!

The giant of planets and quite a monstrosity of swirling gases, Jupiter is the king of the planets. Through the asteroid belt, we arrive at Jupiter, fifth planet from the Sun. With bands of red and white falling and rising gases, Jupiter seems like a huge marble on a racetrack. Named for the Roman god of the sky, Jupiter is mighty and dominant in the solar system, with two and a half times the mass of all other planets in the solar system combined. Jupiter is known for its Great Red Spot, though all gaseous planets have storms. The Great Red Spot is an ongoing storm existing for millenia; about three Earths placed side-to-side can fit across the storm. The storm can attract and suck in weaker storms in its neighborhood. Like the other gaseous planets, Jupiter is mainly hydrogen and helium, the lightest elements. With 71% hydrogen and 24% helium, Jupiter has a composition like that of the primordial solar nebula. Because Jupiter is light for its size, it rotates very fast — its day is less than 10 hours! Though Saturn has noticeable ice rings, Jupiter has only faint rings mainly composed of non-reflective, rocky material. With the most mass, Jupiter has a strong magnetosphere. In fact, if Jupiter were seventy-five times larger, it would have enough pressure and heat inside its core to perform nuclear fusion, produce its own energy, and become a star! But the smallest red dwarfs, or the bare cores of stars, is only three times the mass of Jupiter. Jupiter produces heat in excess to the solar radiation it receives by the Kelvin- Helmholtz mechanism (no heat transfer, by contraction) . By this mechanism, Jupiter shrinks 2 cm per day; Jupiter was actually twice as its current diameter and much hotter at the time of formation. For its interior, scientists are not sure whether Jupiter has a icy or metallic core or even no core at all. Jupiter, does indeed, have a liquid metallic hydrogen layer about 78% of the radius. Droplets of helium and neon precipitate in this layer, so little to none is found in the atmosphere. The liquid metallic hydrogen layer is surrounded by a transparent, supercritical (between liquid and gas phases) hydrogen layer. Water clouds’ polarity in the atmosphere cause lightning 1000x stronger than on Earth and winds often reach 100 mph in zonal (zones and belts on Jupiter, falling and rising gases) jets. In addition, Jupiter has orange and brown clouds that change color when exposed to the Sun’s UV light. Unlike Earth, Jupiter has a low axial tilt, giving less solar radiation to the poles, but convection distributes heat to the poles, balancing the temperatures.

THE GALILEAN MOONS

Jupiter has the most number of moons at 67. All four moons are named after several of many of Zeus’ lovers in Greek Mythology, which seems appropriate since Jupiter is Zeus in Roman form. First discovered in 1610 by Galileo Galilei, Jupiter’s four moons are Io, Europa, Callisto, Ganymede (or IEat Green Carrots). Galileo’s discovery of the moons, initially called Cosmica Sidera (“Cosimo’s stars”) proved that there were other celestial objects orbiting other planets— that everything did not orbit around the Earth. With a telescope you can easily see the four Galilean moons orbiting the planet. You can usually see three or four of the moons; sometimes the moon is positioned behind Jupiter so it is not visible on some nights. Io, Europa, Ganymede, and some of the largest satellites in the solar system form the Laplace resonance; every time Io orbits Jupiter four times, Europa orbits two times, and Ganymede one time. The resonance invokes the moons’ gravitational effects to distort their orbits to be more elliptical. In contrast, Jupiter tidal force, which keeps the moons in orbit, circularizes the orbits. The push and pull heats the moon’s interiors by friction. The closer the moon, the hotter, more active, and denser the moon is; the further the moon, the colder, unchanging, and less dense the moon is.

Jupiter’s moons: Io, Europa, Ganymede, Callisto

IO

Io is the innermost of the Galilean moons and fourth largest moon in the solar system. Its surface ever-changing, Io has over 400 active volcanoes. Some of Io’s more than 100 mountains are taller than Mount Everest! Io has a thin atmosphere comprised of sulfur dioxide and silicate rock surrounding a molten iron or iron sulfide core.

EUROPA

Europa is the second Galilean moon and the smallest, slightly larger than Earth’s moon. In contrast to Io, Europa has one of the smoothest surfaces in the solar system, with a layer of ice and water over the mantle of the planet. Scientists hypothesize that water may exist on Europa and that the planet may house extraterrestrials. Heat energy from tidal flexing, or push and pull of Jupiter and its moons’ gravity, keeps the water liquid. Europa has prominent reddish brown markings that may be volcanic water splitting the surface. It also has an atmosphere of oxygen.

GANYMEDE

Ganymede is the largest natural satellite in the solar system and the third Galilean moon. In fact, Ganymede is larger than even Mercury! Ganymede is icy and the only planet to have a magnetosphere, possibly created by convection with its liquid iron core. Like Europa, Ganymede may also have water (salt), but 200 km below its surface between layers of ice. Its surface comprises of highly cratered dark regions and younger regions with grooves and ridges. Its thin atmosphere includes oxygen, O², and maybe O³ (ozone) and hydrogen.

CALLISTO

Callisto is the last and least dense of the Galilean moons. Callisto has an ancient, heavily cratered and unaltered ice surface. It has a homogenous mix of rock and ice.

This weekend, from Saturday night into Sunday morning (10/21-10/22), you may observe the annual Orionid meteor showers streaking across the sky. Dozens of meteors will scorch the sky every hour.(Of course, the sky must be clear and dark, which, unfortunately, is not for me.) Fortunately, the moon is only in its crescent phase, so its light does not interfere with observing the meteor shower. The Orionid meteor shower happens every year in late October when Earth cross through debris left by Halley’s comet. Halley’s comet last passed through our solar system in 1986, and will not come back until 2061. When Halley’s comet neared the Sun, the heat melted the comet to form gas and dust. Though the comet leaves the solar system, that gas and debris continues to orbit the Sun. Most of the particles that form meteors are only the size of a few grains of sand, but comets have high kinetic energy as they hit Earth’s atmosphere— over 50,000 miles per hour! As the grains, or debris meteoroids, contact Earth’s atmosphere, they ionize molecules in the atmosphere, forming a bright trail across the sky known as a meteor or shooting star. Small meteoroids burn up in Earth’s atmosphere. A meteoroid must be bigger than the size of your fist to survive and hit Earth’s surface. Meteorites are usually found in deserts or Antarctica, where their black coloration stick out easily against the ground. Most meteorites land in the ocean, so no harm done there! In fact, 800 meteorites heavier than 100 grams strike the Earth every day; during meteor showers the frequency is higher.

Orionids Crossing Betelgeuse

Blazin’ Facts

Why “Orionid”? The meteors seem to intersect at Betelgeuse in the Orion constellation (but it’s just an optical illusion).

The Orionids historically have only produced 20 meteors at its peak, but in the last decade, scientists have observed more than 60 meteors per hour!

Meteors travel in space; meteoroids fall though the atmosphere; meteorites strike the surface

Did you know Halley never saw Halley’s comet? Halley suggested that the comet spotted in 1682 was the same one in 1531 and 1607. Halley’s observations led to the conclusion that comets orbit the sun. In 1705, he predicted the comet would appear in 1758, but died before he actually saw the comet.

Aside from Orionids, the other annual meteor shower is the Eta Aquarids that peaks early May.

Curiosity first discovered “Jake Matijevic,” the pyramid rock on Mars, on September 19, 2012, but on October 11, 2012, NASA released a report on the chemical composition of this unusual rock. The rock’s composition was more varied than expected and even resembled some rocks in Earth’s interior. The pyramid rock resembles the common igneous rock found in many volcanic areas on Earth. On Earth, these igneous rocks typically form in the mantle from the crystallization (solidification) of liquid magma at elevated pressure. The first rock analyzed by the rover’s arm-mounted Alpha Particle X-Ray Spectrometer (APXS) and the thirtieth by the rover’s Chemistry and Camera instrument (ChemCam) on September 22, 2012, “Jake” has unique compositions at all 14 points targeted by Curiosity. Analyzing “Jake” marked the first time results of ChemCam were compared with APXS. In addition to the two instruments, Curiosity carries analytical laboratories to provide a more in-depth view of rocks’ and powders’ compositions.

Curiosity’s first scoop of sample from “Rocknest” was perfect. The first scoop is designed to clean Curiosity, essentially like a Martian car wash. Curiosity will spend three weeks at” Rocknest” and then drive 100 yards east to select a rock as its first target for its drill.

What is the universe’s temperature? How has it changed and evolved? What causes the temperature to change? How is the temperature estimated? Is it continuously cooling or constant? –Pcelsus

Black Body Curve of the Cosmic Microwave Background

13.75 billion years ago, the Universe was much smaller and hotter. In the 1960s, Robert Dicke predicted a remnant “glow” from the Big Bang. In 1965 at the Bell Labs, radio astronomers Amo Penzias and Robert Wilson discovered that glow, named the cosmic microwave background radiation. The CBR was seen in all directions in empty space, with a black body curve (temperature ~3K in every direction). About 1 second after the Big Bang, the Universe was very hot, at ~1 billion K. At 3 minutes, protons and neutrons combine to form the nuclei of atoms. As space cooled, material condensed and atomic particles, then elements, molecules, stars, and galaxies formed. The hydrogen/ helium ratio (3:1) found today is about the same as what’s expected after the Big Bang. Atoms were “ionized” with electrons roaming free without being bound. At 300,000 years after the Big Bang, the Universe becomes transparent with a temperature of 3,000K. Light red-shifted by a factor of 1000, and the expansion of the Universe ensued.

Today, the Universe is 2.73K, or 2.73°C above absolute zero, but at the beginning of space and time, the Big Bang, the Universe reached over one billion degrees. From a single pinpoint, the Universe emerged as a scorching hot primordial soup of subatomic particles moving at high velocities. As the Universe expanded, the temperature cooled as more space was created and density decreased. The Universe is continuously cooling as it expands.

Measuring the temperature isn’t as simple as sticking a thermometer in space and waiting until it stabilizes at a certain temperature. Instead, scientists measure indirectly using the cosmic microwave background, or leftover radiation emitted by hot plasma 38,000 years after the Big Bang. As the Universe expanded, the electromagnetic waves of the CMR elongated and decreased in energy, leading to cooler temperatures. Using Planck’s law, scientists measured the black body radiation of the Universe. Planck’s law states that every object radiates electromagnetic energy according to temperature. Black body curves are lopsided, with the curve peaking at different wavelengths depending on the object. In fact, space has a nearly perfect black body curve, since physical objects tend to absorb and reflect light in certain wavelengths.

One hundred yards before its destination, Glenelg, Mars Rover Curiosity scoops samples of rock and soil above and below Mars’ surface for two weeks of instrument cleaning and calibrating. Curiosity must “rinse and spit” to rid its instruments of Earth residue. In a nest littered with rocks, appropriately named “Rocknest,” the rover will scoop four times the ordinary Mars material in preparation for samples at Glenelg. According to NASA, “The end of the rover’s 220-pound arm will shake ‘at a nice tooth-rattling vibration level’ for eight hours, like a Martian martini mixer gone mad. That heavy shaking will vibrate the fine dust grains through the rover chemical testing system to cleanse it of unwanted residual Earth grease.” Before Curiosity can scoop material, it must analyze the grain-size distribution and tread the surface with its wheel to expose new material. It will be two weeks before the rover scoops its first analytical sample, or sample number three (the first two are for cleansing) and even more time to analyze the sample composition. The CheMin instrument will identify minerals and the SAM instrument will identify chemical ingredients in sample three and four.

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Astronomy: To Infinity and Beyond! Welcome to "The Cosmos." I will take you on a journey through our solar system, galaxy, and the Universe! You will be updated with current events in astronomy. Please click on the picture above to visit my blog on poetry, writings, and musings!

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References for photos used from websites can be found under the "References" page. Photo credit: news sites (reference included in post), NASA (most images used), and Google (for artists' view of objects unable to be photographed).